Window unit

ABSTRACT

A prefinished window unit is provided of the type having a sash member with central glazing area, wherein one side of the sash member is designated as the exterior face and the opposite side is designated as the interior face, the central glazing area is bounded by in inner perimetric face, and the sash member is bounded by an outer perimetric face. Each rail of the sash member is formed as a completely prefinished, molded component, requiring no further processing except assembly. The sash members each are integral components having a cellulosic core; an outer coating of synthetic plastic material substantially covering the core from external exposure; and a metal cladding substantially entirely covering the exterior face of the sash member to protect the synthetic coating from ultraviolet degradation. The sash member include slots that receive the glazing strip and weather strip, the slots being defined at least partially by a channel-shaped contour of the metal cladding. In addition, a method of forming molded, prefinished, integral components is disclosed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention generally relates to movable or removable closures,especially to window assemblies. The invention also generally relates tostatic structures, especially composite fabricated panels. A furtheraspect of the invention generally relates to stock material, especiallythat having a structurally defined web or sheet.

2. Description of the Prior Art

Window units have been constructed from many different materials, oftenaccommodating local climate or cost considerations. For example, manyinexpensive windows are constructed with extruded metal frames, whichoffer simplicity of manufacture and dimensional stability, but often arenot thermally efficient or pleasing to the eye. Wooden window frames mayoffer greater thermal efficiency and beauty, but they can be costly dueto greater difficulty of manufacture, and maintenance is often a furtherproblem.

U.S. Pat. No. 4,341,831 to Kleiss discloses an extrusion ofmulti-material construction. An aluminum or other sheet metal core issheathed with polyurethane foam. The Kleiss disclosure explains that theprior art has suffered problems in bonding such a sheathing to a metalcore, and hence, a new bonding material is proposed to cure the problem.Another patent showing a similar end structure is U.S. Pat. No.4,130,976 to Kesseler et al., which uses an aluminum core with a bondedpolyurethane sheathing.

U.S. Pat. No. 3,815,285 to Kuyper discloses a metal shielding that isdesigned to snap on to the exterior of wooden window sash as a weatherprotective device. The advantage gained is in coupling the lowmaintenance of the metal exterior with the beauty and insulating qualityof the wood interior.

While the above noted patents are representative of efforts to improvewindow construction, they do not fully meet the desire of combinedbeauty, insulating value, dimensional stability, manufacturing ease, andlow maintenance. Particularly in new construction, it is desirable toemploy a window unit that is highly efficient in insulating value, bothfrom the standpoint of materials of construction and tightness ofconstruction. Thus, wood or other high insulating material is highlyregarded as the material of construction. If the frame and sash can beproduced in such a way to ensure that the window unit will maintain itsdimensional integrity and structural shape, then the tightness ofconstruction also will be satisfactory.

Additional desirable features of a window unit are that there be littleor no maintenance, while, especially in residential applications, thewindow unit should offer beauty and warmth. Metal extrusions aresatisfactory in terms of requiring little care, but metal does not holdan after-applied finish to a satisfactory degree. Wood is superior interms of beauty and warmth, but maintenance is an on-going requirement.Plastic window constructions are intermediate wood and metal, in thatthey can hold an applied color or be extruded in a selected color. Inaddition, plastic offers good insulating value. However, plastic isknown to degrade under ultraviolet light, which limits the life of suchsynthetic materials, especially in an exterior window construction.Further, plastics tend to be more flexible than metal or wood frame andsash and, thus, may lack the strength to hold a structural shape.

A purpose of the present invention is to provide a window unit havingthe unique combination of a high insulating value similar to that ofwood; low maintenance similar to that achieved with metal; a completesurface finish having the pleasing warmth of wood but that requires nopainting; and the strength and dimensional stability necessary to ensurecontinued performance at their original level for many years. Inaddition, such a window unit should be extremely simple in its method ofmanufacture so that its cost can be close to that of conventional woodand metal windows.

To achieve the foregoing and other objects and in accordance with thepurpose of the present invention, as embodied and broadly describedherein, the membrane and method of manufacture of this invention maycomprise the following.

SUMMARY OF THE INVENTION

Against the described background, it is therefore a general object ofthe invention to provide an improved window unit having compositeconstruction, wherein the components are formed into an integral unitrequiring no further processing or finishing after initial formation.

Another object is to provide a window sash structure that supports theglazing an a stable truss structure, while employing synthetic plasticmaterials for the external configuration of the sash members.

A further object is to provide a method of producing sash members thatembody a composite construction, wherein a single molding processresults in a fully finished member.

Still another object is to produce a synthetic plastic finish on awindow unit, wherein the finish is fully screened from exposure toultraviolet light from the exterior of the window.

Additional objects, advantages and novel features of the invention shallbe set forth in part in the description that follows, and in part willbecome apparent to those skilled in the art upon examination of thefollowing or may be learned by the practice of the invention. The objectand the advantages of the invention may be realized and attained bymeans of the instrumentalities and in combinations particularly pointedout in the appended claims.

According to the invention, a window unit is provided of the type havinga sash member with central glazing area, wherein one side of the sashmember is designated as the exterior face and the opposite side isdesignated as the interior face, the central glazing area is bounded byin inner perimetric face, and the sash member is bounded by an outerperimetric face. The sash member is formed of a cellulosic core; anouter coating of synthetic plastic material substantially covering thecore from external exposure; and a metal cladding substantially entirelycovering the exterior face of the sash member to protect the syntheticcoating from ultraviolet degradation. The sash member includes slotsthat receive the glazing strip and weather strip, the slots beingdefined at least partially by a channel-shaped contour of the metalcladding.

According to another aspect of the invention, a method of formingprefinished sash components includes the steps of providing a moldcavity having the contours of a sash rail having interior and exteriorfaces and inner and outer perimetric faces with mortise and tenon jointends, and having a design patterned surface corresponding to theinternal face of the rail; coating the design patterned face of the moldwith a release agent; placing an elongated core of cellulosic materialin the mold, closely adjacent to the mold wall corresponding to theinner perimetric face of the rail; securing the core in position in themold by placing a metal surface member in the mold in a position closelyadjacent to the exterior face, with marginal portions of the metalsurface member being closely adjacent to the inner and outer perimetricfaces, the marginal portions each including a channel portion thatcontacts the core, wherein the mold cavity includes rib members that fitinto the channel portions and preserve such channel portions as slots inthe finished rail; adding a synthetic plastic resin material to the moldcavity; closing the mold; curing the synthetic plastic resin material toform an integral rail having a cellulosic core, metal cladding on theexterior face and exterior marginal portions of the inner and outerperimetric faces, and synthetic plastic coating of the interior facewith molded surface design; opening the mold; and removing the sashrail.

The accompanying drawings, which are incorporated in and form a part ofthe specification illustrate preferred embodiments of the presentinvention, and together with the description, serve to explain theprinciples of the invention. In the drawings:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a window unit according to the presentinvention.

FIG. 2 is a cross-sectional view of a sash inside check rail, takenalong the plane of line 2--2 of FIG. 1.

FIG. 3 is a cross-sectional view of a sash outside check rail, similarto the view of FIG. 2.

FIG. 4 is a cross-sectional view of a top or bottom rail or stile, takenalong the plane of line 4--4 of FIG. 1.

FIG. 5 is a cross-sectional view of the metal roll form used as acladding.

FIG. 6 is a side view of a four cavity mold used to form the sashmembers of FIGS. 2-5, showing in phantom the cavities partially set upfor molding.

FIG. 7 is a partial top view of the mold of FIG. 8, showing the movablespacer of the cavity that forms the inside check rail.

FIG. 8 is a cross-sectional view of the horizontal members of a windowframe constructed according to the present invention, with sash membersshown in phantom.

FIG. 9 is a cross-sectional view of the vertical members of a windowframe constructed according to the present invention, with sash membersshown in phantom.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

According to the best mode of the invention, the window unit 10 as shownin FIG. 1 is constructed from component pieces that correspond inidentity to those of a conventionally constructed wood window. The sash12 is formed from a pair of opposite horizontal members 14, known as topand bottom rails, and a pair of opposite vertical members 16, whichtogether define the rectangular sash. In a horizontal slide-by window,the vertical rail that fits against the jamb of the window frame may betermed a stile, while the vertical rail that fits against the secondpanel of such a window is termed a check rail, which may be either aninside or outside check rail, depending upon the position of that sashmember in the frame. A sheet of glazing material 18 is carried by thesash and may be mounted in glazing strips 20 carried in grooves thatfollow the inner periphery of the sash. The rails and stiles are joinedtogether by a conventional system of mating tongues. Such window sash 12is carried in or fastened to a frame, which may include a conventionalsill, head jamb, and side jambs formed from components corresponding inidentity to those conventionally found in wood windows.

The sash components are of composite construction, wherein each isprovided with a core of dimensionally stable cellulosic material and anouter covering of synthetic plastic material. In addition, a metalcladding is integrally formed on the outside face of the sash members,while an integral finish is formed on the inside face of each member.Specifically, with reference to FIGS. 2-4, each sash member is providedwith a core 30 of wood-based material such as particle board, whichprovides a strengthening central structural member that is dimensionallystable. Surrounding the core member at least along its longitudinallyelongated sides is a coating 32 of polyurethane having a thickness of asmuch as one-half inch (1.27 cm). This coating is molded to the core andforms an integral unit with the core. Finally, the metal cladding may bean aluminum roll form 34, roll formed to have a labyrinthian transversecross-sectional contour. This external cladding also is molded to thepolyurethane and further is a part of the integral nature of each sashcomponent.

Several configurations of sash components are utilized in production ofa complete window unit, such a double hung window. Each component can beidentified as having several similar characteristic parts when viewed incross-section as in FIGS. 2-4. The rails and stiles each have aninterior face 36, an exterior face 38 opposite from the interior face,an internal perimeter face 40, and an external perimeter face 42. Theseand other similar parts are similarly numbered throughout FIGS. 2-4.

The interior face is relatively designated as the face that will beexposed to the inside of a structure, away from weather and sunlight,whereas the exterior face is directed toward the outside, where weatherand sunlight are expected. However, it may be noted that the exteriorsurface of certain parts such as the sash member of FIG. 2 are notexposed to weather. This sash member, which is an inside check rail, isprotected on its outer, exterior surface, by the outside check rail ofFIG. 3 when the window is closed. Accordingly, no cladding is necessaryon the exterior surface of the inside check rail. The outside check railand the top and bottom rails and stile of FIG. 4, however, are protectedby the cladding.

The internal perimeter will carry the glazing material and,appropriately, is adapted to receive the glazing strip. For example,each internal perimeter includes a retaining ledge or lip 44 near theinterior face 36. Spaced relatively closer to the exterior face is aglazing strip retaining slot 46. Between the ledge 44 and slot 46 is theretaining area 48 that receives and supports the glazing and appropriatespacers. Finally, the external perimeter will contact the sill, jambs,and header. Depending upon the precise application of the component,certain external perimeters and exterior faces may define a weatherstrip retaining slot 50, which receives and supports a sealing strip orbrush that reduces drafts between the moveable adjacent sash or betweensash and frame members. Specifically, the slot 50 in the top or bottomrails and stile of FIG. 4 is in a recess in face 42, where the weatherstrip has room to be compressed without holding the sash at a distancefrom the window frame. Slot 50 in the inside check rail of FIG. 2 is onan angled surface that contacts a similar surface on the outside checkrail when the inside and outside sash units are closed within the frame.

The interior face 36 in all cases is formed from polyurethane so thatthe interior finish is pre-established to a high standard. Thepolyurethane is molded according to known techniques to embody thetexture of wood. Thus, the interior can be modeled after selectedexcellent specimens of actual wood, producing a uniformity of beauty ineach window. The external perimeter 42 also is molded from polyurethane.

The exterior face 38 includes a polyurethane body, but in all cases theportion of the exterior face that will be exposed to direct sun light isclad with a protective material, such as metallic aluminum. Thus, thealuminum roll form 34 is located directly on the surface of the exteriorface. As shown in FIG. 5, this roll form includes an outer face 52 thatis the immediate outer surface of the exterior face. On the externalperimeter face, the roll form follows first an outermost wall portion54, then an inward offset wall 56, and an inset wall portion 58. Nearits termainal edge, the roll form forms a U-shaped groove or channelslot 60 that opens outwardly to simulate the configuration of a sawkerf, as is used in conventional wood windows to hold the weather strip.On the internal perimeter face, the roll form includes an outer wall 62and a terminal U-shaped channel slot 64, again simulating a saw kerf,but for the purpose of receiving a glazing strip.

The internal perimeter face 40 may have the cellulosic core 30 exposedat the glazing support area 48, although the portions of face 40 ateither side of this area, including the ledge 44 and retaining slot 46,are formed of polyurethane. By this construction, the cellulosic core 30provides a substantial majority, if not all of the surface area in theglazing support area and is placed in direct structural contact with theglazing and its support strips, providing a rigid and durable trussstructure to hold the glass in place. Equally as important is that themore complex structure of the retaining slots 46 and ledge 44 be in thearea of molded plastic material so that these structures can be formedwithout the need to process the sash members specially for this purpose,as with a router or saw.

The method of manufacturing the sash members is such that each member isproduced in fully finished form and requires no processing or surfacefinishing before assembly into window units. This method employs amolding process, where a four cavity mold 66 as shown in FIG. 7 can beemployed to produce at least one of each of the previously describedsash members with each cycle. The cavities 68, 70, and 72 produce sashmembers corresponding to the sash members of FIGS. 2-4, respectively,and cavity 74 produces a second top or bottom rail or stile member,which is the most frequently used member. Each cavity employs a rubberliner 76 that carries the configuration of an actual wood surface. Theliner 76, in each instance, is applied against the surface of theinterior face 36 of the respective sash members, with the addition that,in cavity 68, the liner includes an additional portion 78 that isapplied against the external perimeter face 42 of the inside check railof FIG. 2. The inside check rail of a double hung window or horizontalslide-by window has its external perimeter surface is visible, and,thus, such surface is given a decorative finish.

In cavities 70-74, the cross-section of the cavity conforms in detail tothat of the desired product except for the presence of slots 46 and 50.The internal perimeter face 40 is located at the bottom of each of thesecavities, permitting the cavities to be loaded initially with thecellulosic core piece 30. These core pieces 30 are held in place notonly by gravity, but also by locator means such as portions of the rollform 34, as will be described below. Next, the aluminum roll form 34 isplaced in the cavity with outer face 52 against the cavity side wall 80opposite from the liner 76. A rib 82 at the bottom face of each cavityextends upwardly to be engaged in slot 64 of the roll form, therebyholding the roll form in fixed position and preventing entry ofpolyurethane into these slots during molding. The mold lid 84 includeskeying protrusions 86 that engage the offset wall 56 of the roll form 34when the mold is closed to assure that the roll form remains in theproper position. The protrusions 86 also seal against the open faces ofslots 60, thereby preventing entry of polyurethane into these slotsduring molding.

The aluminum roll form 34 serves as a locator means to hold the core 30in the desired position within the mold cavity. As shown in FIG. 6, theslots 60 and 64 become stops to properly position the core 30. The slotside wall of slot 64 limits lateral travel of the core, while the slotbottom wall of slot 60 limits vertical travel of the core. When the coreand the roll form have been loaded into the mold, both have a stableposition by virtue of their interaction.

The sash member of FIG. 2 is molded in a diagonal position, wherein theinterior face 36 and external perimeter face 42 are molded against thebottom two surfaces of the mold. Thus, the mold base 66 contains themolding surface for faces 36 and 42, while the mold lid defines thesurfaces to form faces 38 and 40. Accordingly, cavity 68 receives thecore 30 in a suspended position, with the glazing area being a diagonaltop surface. A retractable spacer 88 in the side of the mold assistholding the core in its proper place during assembly, and a registeringsurface 90 of the lid 84 is applied against the core during the moldingprocess to ensure that the core is properly located. In addition, theslots 46 and 50 must be formed by moveable, retractable ribs 92 and 94,respectively, carried by the lid 84. These ribs are retracted after themolding process, as they otherwise would be cause lid 84 to be molded inplace after the molding process was complete.

The spacer 88, best shown in FIG. 7, slides into cavity 68perpendicularly to what will be glazing support surface 48 in thefinished mold product. The spacer establishes a slot in the end of thefinished product, permitting a mortise and tenon joint to be used whenthe finished product is assembled with remaining sash members. The moldincludes a slot 96 to receive the T-head of the spacer, and the depth ofthe slot 96 limits the travel of the spacer into the mold.

The molding process requires, first, that the mold cavities and blankets76 be treated with a release agent such as a barrier coat material thatassists in releasing the urethane from the RTV silicone of the cavity,and which also provides pigment and ultraviolet protection to the woodgrained portion of the molded sash pieces. The cores 30 and roll forms34 then are loaded into the corresponding cavities. Polyurethane resinis poured to fill the remaining open areas, after which the mold isclosed. The ribs 92 and 94 are extended to enter the channels of theroll forms, after which the resin is cured. Ribs 92 and 94 are retractedfrom cavity 68, after which the mold is opened. Spacer 88 is withdrawn,and the sash pieces are removed.

The pieces so removed are in finished form and can be assembled into arectangular sash as shown in FIG. 1, generally by mortise and tenonjoints. Weather strip is inserted in roll form slots 50 formed bychannels 60. The glazing, spacers, and glazing strip are then put inplace, with the glazing strip being placed in slot 46, formed by channel64.

It is notable that the finished product has no synthetic plastic surfaceon the exterior face directly exposed to sunlight. The aluminum rollform clads all externally exposed surfaces. The glazing strip covers andprotects the glazing area from the roll form to the ledge 44. Finally,the glazing material serves as an ultraviolet light filter to protectthe wood grained polyurethane from the ledge to the interior face of thewindow unit.

The sash has been described completely, and the frame surrounding thesash is formed along similar lines. With reference to FIGS. 8 and 9, atypical frame and sash panel combination is shown for horizontal side-bywindows. The frame is formed of side jambs 98, a head jamb 100, and asill 102. These are covered with an extruded aluminum cladding and carryan aluminum nailing flange 104 to permit attachment of the window to theframe of a building structure. The jambs and sill of the frame aremolded of polyurethane having a cellulosic core 106, similar to core 30of the sash members.

Metal extrusions cover the parts of the frame that are exposed toweather. The sill 102 is not only covered by a cladding 108, but iscontoured into an outwardly extending sill portion 110 formed entirelyfrom aluminum. The head jamb 100 and side jambs 98 include cladding 112having outward extensions 114 of extruded aluminum. The outwardextensions 110 and 114 are contoured to form a slot 116 that receivesthe nailing flange 104.

The frame further includes both decorative and functional componentsthat enhance the appearance and operation of the window unit. Interiortrim pieces 118, FIG. 8, are of molded polyurethane, having a woodfinishsurface appearance. The sill track 120 and head track 122 are ofextruded PVC for lubricity. A flexible open cell urethane compressionmember 124 is located between the head track and head jamb. As is bestshown in FIG. 8, the horizontal sash members, such as bottom rails forthe inside and outside sash panels, slide on the sill track.

The assembled sash panels are tightly sealed against air penetration.The vertical sash members, such as inside and outside check rails, aresealed between themselves by bulb weatherstrip 126, shown in FIG. 8. Thevertical stiles seal against the side jambs with similar weatherstrip,as shown in FIG. 9, thus sealing the sash to the frame. The frame thusdisclosed further lends itself to use with conventional screens, whichmay be placed between the slot channel 116 and the surface cladding onthe jambs.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be regarded as falling within the scope of the invention as definedby the claims that follow.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A method of formingprefinished sash components, comprising:providing a mold cavity havingthe contours of a sash rail having an interior and an exterior face, aninner and an outer perimetric face, and mortise and tenon joint ends,said mold cavity having a design patterned surface corresponding to theinternal face of the rail; coating said design patterned surface of themold with a release agent; placing an elongated core of cellulosicmaterial in the mold, closely adjacent to said mold wall correspondingto the inner perimetric face of the rail; securing said core in positionin the mold by placing a metal surface member in the mold in a positionclosely adjacent to said mold wall corresponding to the exterior face ofthe rail, with marginal portions of the metal surface member beingclosely adjacent to said mold walls corresponding to the inner and outerperimetric faces of the rail, said marginal portions each including achannel portion that contacts the core, wherein the mold cavity includesrib members that fit into said channel portions and preserve suchchannel portions as slots in the finished rail; adding a syntheticplastic material to the mold cavity; closing the mold; curing saidsynthetic plastic material to form an integral rail having a cellulosiccore, mortise and tenon joint ends, metal cladding on an exterior faceand exterior marginal portions of an inner and an outer perimetric face,and synthetic plastic coating on an interior face with molded surfacedesign; opening the mold; and removing the sash rail.
 2. The method ofclaim 1, wherein said core is placed in the mold in a position restingon the surface corresponding to the inner perimetric face, such that thecore is exposed on the inner perimetric face of the molded rail.
 3. Themethod of claim 1, wherein said mold cavity includes an insertable andremovable spacer means defining a mortise gap in said mold cavity endcorresponding to a joint end of the rail, further comprising:prior tothe step of closing the mold, inserting the spacer means into thecavity; and before the step of removing the sash rail, removing thespacer means.
 4. The method of claim 1, wherein said rib members arecarried in the mold on extendable and retractable mountings, furthercomprising, immediately after the step of closing the mold, extendingthe rib members into said channel portions of the metal surface member;and immediately before the step of opening the mold, retracting the ribmembers from the channel portions.